30万15年,mortgage is about $2500. Tax is $750/mo. insurance is $30/mo. This total is $3300. LZ's income is 75K. Monthly income after tax is about $4500. Only $1200 left for utilities, food, phone, internet, TV, cars, I don't suggest you to buy this house.
then you cannot afford it using 15-y loan. The true monthly pay will be at least $3300. You cannot afford it. If you live in an area where housing price up 5%+ a year, then 3 or 5y ARM is good choice, you will sell your house in a few years. Or go with other's people suggestion, 15% down 30y loan, keep $100K cash at hand.